Apparatus for separating particulates from a suspension, and uses thereof

ABSTRACT

The present invention includes an apparatus for separating particulates from a fluid in a suspension, comprising: a housing defining a frusto-conically shaped inner chamber with an inner wall, an inlet and a first outlet communicating with the chamber, and a second outlet; and a spinning assembly with a hollow interior mounted in the chamber, the assembly being shaped to define an annular gap with the chamber inner wall, the hollow interior communicating with the second outlet, and the hollow interior communicating with the annular gap for flow of fluid materials from the gap into the interior and out of the second outlet in response to rotation of the spinning assembly. The separator finds application in the preparation of waste products such as municipal sewage sludge for processes that produce useful materials including gas, oil, specialty chemicals, fertilizer, and carbon solids, in reliable purities and compositions, and with high energy efficiency.

CLAIM OF PRIORITY

This application claims the benefit of priority under 35 U.S.C. § 119(e)to U.S. provisional application Ser. No. 60/458,520, filed Mar. 28,2003, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to the separation ofparticulates from a fluid suspension. More specifically, the inventionrelates to a separator that separates out particulates of a dimension ofabout 1 micron, such as cellular debris from bacteria, from asurrounding fluid. The apparatus of the present invention findsparticular application in the processing of waste or low-value productssuch as municipal sewage sludge to form useful raw materials.

BACKGROUND

It has long been recognized that many of the waste products generated byhuman society can, ultimately, be broken down into a small number ofsimple organic materials that have their own intrinsic value. If thistransformation could be achieved in an energy-efficient manner, and on alarge enough scale, then there could be enormous benefits to society.

Most living materials, as well as most synthetic organic substances usedin domestic and commercial applications comprise carbon-based polymersof various compositions. Under appropriate conditions, most suchmaterials—including wood, coal, plastics, tires, and animal waste—willbreak down to a mixture of gaseous products, oils, and carbon. Materialssuch as agricultural waste products may also contain inorganicsubstances that break down to mineral products. Almost all of theseproducts, whether organic or inorganic, can enjoy new lives in a host ofbeneficial and often lucrative applications.

Not only is the principle of creating useful materials from otherwiseunserviceable waste appealing: recycling of waste materials is offundamental importance to the way that the burgeoning human populationwill come to cope with major challenges in the 21^(st) century. Twoprincipal challenges facing humanity are coping with a finite supply ofmaterials and energy, and with curtailing the growing threat to theenvironment from global warming. Indeed, an idea that is rapidly gainingcurrency is that recycling carbon-based materials from within thebiosphere rather than introducing new sources of carbon from undergroundoil, natural gas and coal deposits could mitigate global warming.

As of today, however, industries that produce huge volumes of wasteproducts comprising largely organic materials face enormous challengesin disposing and storing that waste, as well as putting it to maximumbeneficial use.

A case in point, the food processing industry around the world generatesbillions of pounds of organically rich wastes per year. These wastes areassociated with the processing of both animal and plant products, andinclude turkey-, fish-, chicken-, pig-, and cattle-processing andhusbandry wastes. The food processing industry continues to grow and itsmembers face significant economic and environmental pressures to dosomething productive with their waste products. Such waste products giverise to a number of critical problems. The generation of greenhousegases such as carbon dioxide and methane by landfilling, land applying,or digesting food wastes, without any other benefit, is one suchproblem. Ideally, the food industry must adopt efficient and economicalways of managing their wastes without discharging odorous orobjectionable pollutants.

More recently, the cost of warehousing unusable byproducts in many areasis growing in significance. As the types of waste products that can befed to agricultural livestock become increasingly regulated. Forexample, in the wake of BSE/CJD scares in Europe, many waste productsare simply being warehoused, pending a suitable fate. Clearly, there isan additional urgent need to find an acceptable means to cleanly processand utilize such materials. Preferably, a way to convert food-processingwastes into useful, high-value products needs to be found.

An additional drive to seek treatment alternatives is the combinedenforcement of wastewater discharge regulations and the escalation ofsewage surcharges. The food processing industry must seek cost-effectivetechnologies to provide pretreatment or complete treatment of theirwastewaters and solid (wet) wastes. Historically, food processingfacilities located within or adjacent to municipalities, have relied onlocal publicly owned treatment works (POTWs) for wastewater treatmentand disposal. Increasingly, this option is becoming less available, as aresult of more rigorous enforcement. Pressure to comply with wastewaterdischarge permits has increased. Dwindling federal grants forconstruction of new and upgraded POTWs also mean that this option isless appealing. Thus, the food-processing industry is increasingly beingpressured with regard to how to effectively dispose of its inedibleproducts.

Bioaccumulation of persistent chemicals such as dioxins and thepotential for the spread of life threatening diseases such as Mad CowDisease (BSE) is another threat to food processors and food consumersalike. This threat is greatly exacerbated by refeeding food processingresidues to farm animals. Food processors need economical solutions tobreak this cycle.

Furthermore, municipal and regional sewer authorities are requiringindustries to reduce their organic biochemical oxygen demand (BOD),chemical oxygen demand (COD), and solid loading on the sewers. Due tothe high BOD concentrations typically found in high-strength foodprocess wastewaters with high levels of suspended solids, ammonia, andprotein compounds, the food processing industry is under additionalscrutiny. Food processing facilities need cost-effective andapplication-specific treatment technologies to manage their wastewatersand solid wastes effectively.

Similar problems are multiplied, magnified and augmented in manydifferent ways across other industries. For example, the generation ofmalodorous air emissions associated with rendering plants—that convertanimal waste by heat into fats and proteins, is one such problem.Another is land application of municipal biosolids that contain highconcentrations of pathogens.

There have been various approaches developed to process used wastetires, say from truck and passenger vehicles, into useful productsincluding fuels, petroleum oils, carbon, fuel-gases, and feedstocks formanufacture of tires and other rubber products. Typically, these schemesinvolve heating and dissolving the tires in solvents. Some of theschemes attempt to devulcanize the tire rubber, i.e., break the sulfurbonds that connect the constituent polymers along their lengths. Othersattempt to depolymerize the rubber material. Depolymerization breaks thelong chain polymers into shorter ones that are more fluid so can moreeasily be used as a product such as a fuel oil. Some schemes involve theuse of water under conditions near or above its critical point (˜3,200psi and˜370° C.) where water is a very good solvent for, and reactantwith, the tire material. However, such schemes are energeticallyinefficient because of the energy required to achieve super-criticalconditions. Furthermore, processing at super-critical conditions alsorequires expensive super-alloy operating equipment.

A number of organic materials have also been investigated for dissolvingtire material to form a heavy oil or a devulcanized rubber product.Generally, the existing schemes that operate at modest conditions (<200psi) produce heavy, contaminated products, whereas those that uselighter solvents produce better products but must use a solvent that isexpensive, or that requires high pressure (<2,000 psi), or both.Additionally, most schemes that use a solvent to dissolve tire materialare uneconomical because some fraction of the solvent is lost during theprocess and there is a cost associated with the make-up solvent, even ininstances where solvent recovery and reuse can be practiced.

Aerobic and anaerobic digesters have been employed at sewage treatmentplants to treat municipal sewage sludge. There are a number of problemsassociated with their use. The basic principle behind their operation isthat biologically rich materials are directed into large holding vesselsthat contain bacteria which digest the biological materials. Typically,dissolved solids are directed to an aerobic digester, and suspendedsolids are directed to an anaerobic digester. Once the nutritional feedmaterials are exhausted, the bugs can no longer sustain themselves, andthey die. The end-product of the digestion period is a sludge thatcontains the dead bacteria, and which must be disposed of in some way.One problem with the resulting material is that it still containspathogens. Problems with the whole process, in general, include that theholding times in the digester vessels can be as long as 17 days, andthat the operating conditions are difficult to maintain. For example,the relatively large vessel (typically 20–30 ft. in diameter) is usuallymaintained at above 85° F., and in some cases above 122° F.

All of the disposal technologies currently available to industries, inparticular the food processing industry, have significant limitationsand drawbacks that provide an incentive to search for alternativeprocesses. This applies to technologies in addition to the use ofexisting POTWs. In particular, four types of approach, land disposal(landfills, composting, land application), biotreatment, traditionalthermal oxidation treatments such as incineration/combustion, andpyrolysis/gasification, all have separate drawbacks.

Drawbacks for land disposal include: high haulage or transport costs,significant potential for groundwater contamination from leaching, andthe exposure of area residents to high concentrations of hazardouspollutants (such as pathogens in the instance of land application).Landfills produce gas that can create air pollution concerns, includingthe generation of greenhouse gases.

Disadvantages for biotreatment of waste include difficulty with control,and inability to verify performance because of the difficulty withverifying adequate airflow into the soil. The airflow must be maintainedto provide oxygen if using aerobic bacteria. For example, bacteria thatmay have been developed to consume specific compounds will, when placedin soil, activate alternative enzyme systems to consume the easiestavailable compounds.

Drawbacks with older units that carry out incineration or combustioninclude the requirement to add equipment to meet air pollution emissionstandards that are continually being made more stringent by thegovernment. It may also take longer to obtain air discharge permits forincinerators than for other technologies due to significant communityconcerns about incineration. Additionally, the treatment of the waste atthe exhaust means treating large volumes of gas so that very large plantequipment is required. The feedstock is also low in calorific value.Some incinerators are not compatible with solid fuels or solid waste, asthese materials will start to oxidize too high up in the furnace.Conversely, high moisture content in the feedstocks is also a problembecause during incineration or combustion the water is vaporized andremoved—a process which requires approximately 1,000 Btu/lb of watervaporized. This represents huge heat/energy losses to the system.

The last category of technique employed—pyrolysis/gasification—isappealing because, unlike the others mentioned, it attempts to convertthe waste into utilizable materials, such as oils and carbon. Ofprincipal concern when searching for optimum ways of breaking down wasteproducts is how to adjust the composition of the resulting materialswhile minimizing the amount of energy needed to effect the breakdown. Inthe past, the principal pyrolysis and gasification methods that havebeen employed attempted to break down the waste products in a singlestage process, but a single stage has been found to offer inadequatecontrol over purity and composition of the end products.

Pyrolyzers have been used to break down organic materials to gas, oilsand tar, and carbonaceous materials. A pyrolyzer permits heating of theorganic materials to high temperatures, ˜400–500 ° C., but has poorenergy efficiency and gives little control over the composition of theresulting materials. In particular, most waste products—especially thosefrom the agricultural industry—contain up to 50% water. The pyrolyzerneeds to boil off that water, a process that is very energeticallydemanding. Additionally, a pyrolysis chamber tends to be large in orderto maximize throughput, but then gives rise to significant temperaturegradients across the chamber. Thus, the pyrolysis process involves anuneven heating of the waste products and leads to poor quality or impuretars and oils in the resulting end products.

Gasifiers have been used to achieve a partial combustion of wasteproducts. In essence, a gas—usually air, oxygen, or steam—is passed overthe waste products in an amount that is insufficient to oxidize all thecombustible material. Thus, some combustion products such asCO₂,H₂O,CO,H₂ and light hydrocarbons are produced, and the generatedheat converts the remaining waste products into oils, gases, andcarbonaceous material. The gases produced will contain some of the inputgases, but any gases that are produced are too voluminous to be storedand must be used immediately or piped to a place where they can beutilized. Gasifiers also suffer from some of the same drawbacks aspyrolyzers: for example, a water-containing waste product will consume alot of energy in vaporizing the water content.

Both pyrolysis and gasification methods additionally have the problemthat the resulting materials contain unacceptable levels of impurities.In particular, sulfur—and chlorine-containing materials in the wasteproducts give rise, respectively, to sulfur-containing compounds such asmercaptans, and organic chlorides in the resulting end products.Typically, chlorinated hydrocarbons at levels of 1–2 ppm can betolerated in hydrocarbon oils, but neither gasification nor pyrolysismethods can guarantee such a low level with any reliability.

Furthermore, pyrolysis and gasification methods have low efficiencies,typically around 30%. One reason for this is that the products are notoptimum in terms of calorific content. A further reason is that, in asingle stage process, the materials are not produced in a form thateasily permits their energy to be use fully re-used within the process.For example, it is difficult to capture the thermal energy in the solidproducts that are produced and redirect it to assist in the heating ofthe reaction vessel.

Overall, then, pyrolysis/gasification methods suffer in several ways.The oil product is generally rich in undesirable high viscositycomponents such as tar and asphalt. Both pyrolysis and gasificationprocesses have poor heat transfer properties and consequently do notheat evenly. Therefore, end products vary greatly in number with few ofsufficient quantity or quality for economical recovery. Wet feedstocksrequire significant energy to vaporize and represent large energy lossesto the system since the water leaves as a gas in the stack. Thus, insummary, the disadvantages of pyrolysis/gasification are that theoverall operating cost is high, the process is capital intensive andsome by-products may have limited or no value.

Although there have been many variants of the pyrolysis and gasificationmethods, all of which have suffered from broadly similar drawbacks, onerecent advance has permitted significant increases in processingefficiency. For example, U.S. Pat. Nos. 5,269,947, 5,360,553, and5,543,061, disclose systems that replace the single-stage process of theprior methods with a two-stage process. In a first stage (often referredto as the “wet” stage), the waste products are subjected to heat ataround 200–250° C. and at about 20–120 atmospheres pressure. In apreferred embodiment, the waste products are subjected to a pressure ofabout 50 atmospheres. Under such conditions the water content of thewaste material hydrolyzes many of the biopolymers such as fats andproteins that may be present to form a mixture of oils. In a secondstage (often called the “dry” stage), the mixture is flashed down to lowpressure, during which around half of the water is driven off as steam.The mixture is heated still further to evaporate off the remaining waterwhile the mixture ultimately breaks down into gaseous products, oils,and carbon.

The principal advance of these two-stage methods was to permitgeneration of higher quality and more useful mixtures of oils than anyof the previous single stage processes. However, the products of suchmethods still suffer from problems of contamination, from materials suchas sulfur—and chlorine-containing compounds, and the need to evaporate asignificant portion of the water still entails a substantial energypenalty. Thus, prior two stage methods have been difficult to makecommercially viable.

Accordingly, there is a need for a method of processing waste andlow-value products to produce useful materials in reliable purities andcompositions, at acceptable capital and operational cost.

SUMMARY OF THE INVENTION

The present invention includes an apparatus for separating particulatesfrom a fluid in a suspension, comprising: a housing defining afrusto-conically shaped inner chamber with an inner wall, an inlet and afirst outlet communicating with the chamber, and a second outlet; and aspinning assembly with a hollow interior mounted in the chamber, theassembly being shaped to define an annular gap with the chamber innerwall, the hollow interior communicating with the second outlet, and thehollow interior communicating with the annular gap for flow of fluidmaterials from the gap into the interior and out of the second outlet inresponse to rotation of the spinning assembly. In an embodiment of theapparatus for separating particulates, the spinning assembly furthercomprises: a hollow spindle defining a spindle inlet and a spindleoutlet, the spindle outlet communicating with the housing second outlet;and a tapered, porous cylindrical wall mounted on the hollow spindle todefine the hollow interior, the hollow interior communicating with thehollow spindle through the spindle inlet.

The present invention further includes an apparatus for separatingparticulates from a fluid in a suspension, comprising: a casing havingan inner surface; a tapered cylinder disposed in the casing having alongitudinal axis, an angle of taper, and having a porous wall with anouter surface configured to form an annular gap between the outersurface and the inner surface of said casing, said tapered cylinderbeing concentrically mounted on a hollow spindle so that it can becaused to rotate about its longitudinal axis; an inlet for introducingthe suspension into the annular gap at a flow rate; a first outlet inthe casing for permitting separated particulates to be released from thedevice, upon rotation of the cylinder; and a second outlet in the hollowspindle for permitting fluid that passes through the porous wall to bedrained from the device, upon rotation of the cylinder.

The separator of the present invention finds application in theprocessing of waste and low-value products to produce useful materialsin reliable purities and compositions, at acceptable cost, withoutproducing malodorous emissions, and with high energy efficiency. Theseparator of the present invention is particularly applicable to thepreparation of organic and inorganic waste such as municipal sewagesludge for processing in a multi-stage process that converts the sludgeto useful materials including gas, oil, specialty chemicals (such asfatty acids), fertilizer, and carbon solids.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flow-chart of an overall process according to the presentinvention;

FIG. 2 shows an apparatus for performing a process of the presentinvention;

FIG. 3 shows a flow-chart of a preparation and first stage reaction of aprocess of the present invention;

FIG. 4 shows a flow-chart of a second, separation stage of a process ofthe present invention;

FIG. 5 shows a flow-chart of a third stage reaction of a process of thepresent invention;

FIG. 6 shows an apparatus for carrying out a third stage of the processof the present invention;

FIG. 7 shows an apparatus for separating fine suspended solids from afluid; and

FIGS. 8A and 8B show use, respectively, of a third stage reactor and acooler/condenser with a process according to the present invention.

DETAILED DESCRIPTION

The process of the present invention is directed to producing one ormore useful materials from low-value or waste products generated bysociety at large, either from ordinary domestic practices, or fromcommercial operations. Typically the process of the present invention isapplied to waste products, or other low-value products, for examplegrease, that contain a substantial proportion of organic materials.However, the present invention may be applied to convert other products,not normally considered low-value, to higher-value products.

Organic materials are those commonly understood by one of ordinary skillin the art. In particular, for use with the present invention, organicmaterials are those materials whose constituent elements include carbonin combination with one or more other elements such as hydrogen, oxygen,nitrogen, sulfur, and phosphorous, and the halogen elements, inparticular fluorine, chlorine, bromine, and iodine. For the purposes ofthe present invention, organic materials also include compounds thatcontain carbon in combination with elements such as arsenic, selenium,and silicon, as well as salts of organic molecules, and complexes oforganic molecules with metals such as, but not limited to, magnesium,mercury, iron, zinc, chromium, copper, lead, aluminum, and tin. Manyorganic materials used with the present invention come from biologicalsources and comprise proteins, lipids, starches, nucleic acids,carbohydrates, cellulose, lignin, and chitin, as well as whole cells.Other organic materials for use with the present invention, haveman-made, or synthetic origin, such as plastics, and otherpetroleum-derived products.

In the process of the present invention, heat and pressure are appliedto a feedstock at the levels needed to break the feedstock's longmolecular chains. Thus, feedstock material is broken down at themolecular level to one or more constituent materials. In the process,the feedstock is transformed from a cost or low value to a profit, orsignificant cost reduction, or higher value. Importantly, the process isable to destroy pathogens.

The basic process of the present invention is designed to handlepotentially any waste or low-value product, including: by-products offood manufacture and distribution such as turkey offal, fryer oils, cornstalks, rice hulls, waste scraps, last-press edible oils such as canola,soybean, palm, coconut, rape seed, cotton seed, corn, or olive oil, andother oils, food processing wastes, and seafood industry wastes;by-products of paper and other wood industry manufacturing, such ascellulose and lignin by-products, and paper-pulp effluent; yard wastesuch as leaves and grass clippings; tires; plastic bottles;harbor-dredged sediments; post-consumer plastics and electronics, suchas old computers; municipal solid waste; oil-refinery residues;industrial sludges; bagasse; seaweed; milling waste; black liquor; coalrefinery wastes; tar sands; shale oil; drilling mud; cotton waste;agricultural processing wastes such as animal manures; infectiousmedical waste; biological pathogens; and even materials such as anthraxspores that could be used to make biological weapons. It is to beunderstood that the foregoing list of materials is not an exhaustivelist. In the foregoing list, bagasse is a byproduct from processing ofsugar cane, and black liquor is a byproduct of chemical wood-pulpingthat results from dissolving wood chips, liberating the lignin, andfreeing the fibers to give rise to a lignin and hemi cellulose solution.

Waste products for use with the present invention are typicallybyproducts or end-products of other industrial processes, commercialpreparations, and domestic or municipal uses, that typically have noother immediate use and/or which are ordinarily disposed of. Low-valueproducts may similarly be byproducts or end-products of other industrialprocesses, commercial preparations, and domestic or municipal uses, butare typically materials that have very low re-sale value and/or whichrequire some further processing to be converted into something of use.

When used with the process of the present invention, waste and low-valueproducts are typically referred to as feedstocks or as raw feed. It isalso to be understood that the raw feed used with the process of thepresent invention can comprise waste and/or low-value products from anumber of sources, and of a number of different types. For example,food-processing wastes could be combined with agricultural processingwastes, if convenient, and processed simultaneously.

Still other exemplary raw feed materials for use with the presentinvention include municipal sewage sludge, mixed plastics (includingpolyvinylchloride (“PVC”)) as might be obtained from a municipalrecycling depot, and tires.

Polyvinyl chloride (PVC) is found in vinyl siding and plastic plumbingpipes. PVC contains about 55% by weight chlorine and thus has apropensity to give rise to harmful chlorine-containing compounds whendegraded. For example, combusting PVC produces dioxins, which are someof the most toxic compounds known. One benefit of using water early inthe process of the present invention is that the hydrogen ions in watercombine with chloride ions from the PVC to yield solubilized productssuch as hydrochloric acid, a relatively benign and industrially valuablechemical which is useful for cleaners and solvents.

Tires are typically obtained from vehicles such as automobiles, buses,trucks, aircraft, and other mass-transit craft, as well as military andother commercial vehicles. When applying the process of the presentinvention to tires, a portion of the produced oil is preferably recycledto the inlet to assist dissolving the tires in the incoming feedstock.

Waste and low-value materials processed by embodiments of the presentinvention are generally converted into three types of useful materials,all of which are both valuable and are not intrinsically harmful to theenvironment: high-quality oil; clean-burning gases; and purified solidsincluding minerals, and carbon solids that can be used as fuels,fertilizers or raw materials for manufacturing. Additionally, variousside-streams are produced during the process of the present invention,including in some instances to concentrates similar to “fish solubles.”Typically, useful materials are considered to be those that have ahigher economic value than the waste, low-value or other materials thatserved as the feedstock. Such useful materials may have, for example,higher calorific content, or may have a wider range of applications thanthe feedstock from which they were derived.

The process of the present invention comprises a number of stages, asillustrated in FIGS. 1 and 2. FIG. 1 shows, in outline, principalfeatures of an embodiment of the process of the present invention. FIG.2 shows an exemplary apparatus 200 for carrying out a process accordingto the present invention.

The raw feed 100, shown in FIG. 1, may potentially be any waste productor low-value organic and/or inorganic stream. Preferably, the raw feedcontains a substantial amount of carbon-containing material.

Raw feed 100 is subjected to a preparation stage 110. An aspect of thepreparation stage is to reduce the size of the raw feed using pulpingand other grinding technologies to a size suitable for pumping. Thepreparation stage may comprise one or more steps, and may compriseadding materials to, or driving materials off from the raw feed, andresults in a slurry 112 that is passed to a first stage 120. Slurryingmay involve adding water (or other suitable fluid) to raw feed 100,depending upon its initial water content. Use of a slurry is beneficialbecause wet grinding, as in the preparation stage 110, reduces frictionand energy consumption, and because a slurry may be easily transferredby pumps from one vessel to another. Suitable slurrying devices include:a pulper, an in-line grinder, or a maserator. A mixture of steam andgases 121 is given off from preparation stage 110.

In a first stage 120, the slurry is subjected to heat and increasedpressure wherein the slurry undergoes a first reaction, also called afirst stage reaction. Such conditions of heat and pressure lead tobreakdown of the cell structure of biological components of the slurry,to release constituent molecules such as proteins, fats, nucleic acids,and carbohydrates. Additionally, many polymeric organic materials arehydrolyzed by water in the slurry to mixtures of simpler organicproducts. In particular, fats may be partially split to give floatableorganic materials such as fatty acids (containing carboxylic acidgroups), and water soluble glycerols (i.e., molecules containing 3hydroxyl groups). Proteins are typically broken down into simplerpolypeptides, peptides, and constituent amino acids. Carbohydrates arelargely broken down into simpler, water soluble, sugars. Furthermore,the presence of water in the first stage is advantageous because ithelps convey heat to the feedstock.

It is to be understood that the terms react, reacting and reaction, whenused in conjunction with embodiments of the present invention, canencompass many different types of chemical changes. In particular, theterm reaction can encompass a chemical change arising from thecombination or association of two or more species that give rise to oneor more products, and can encompass other types of decompositions orconversions that involve the breakdown or transformation of a singlespecies, as induced by conditions of temperature, pressure, or impact ofelectromagnetic radiation, and can further encompass transformationsinvolving a solvent, such as a hydrolysis. It is further to beunderstood that when the term “reaction”, or “react” is used herein todescribe a process, or a stage in a process, then more than one chemicalchange can be occurring simultaneously. Thus, a reaction cansimultaneously involve a hydrolysis and a decomposition, for example.

A mixture of steam and gaseous products 126 is typically liberated fromthe slurry in the first stage 120. The reacted feed 122 resulting fromthe first stage typically consists of a mixture of reacted solidproducts and a mixture of reacted liquid products. These variousproducts are typically characterized as an oil phase, a water phase, anda wet mineral phase. The water phase and the oil phase typically containvarious dissolved organic materials. The mixture of steam and gases 126produced in the first stage 120 is preferably separated by a condenser,and the steam is used to pre-heat incoming slurry.

The reacted feed 122 is then subjected to a separation stage 130 inwhich a further mixture of steam and gases 132 is driven off, and amixture of minerals 134 or other solid materials is separated out.Preferably, the solid materials obtained at this stage do not comprisecarbon solids, unless carbon solid was present in the input feedstock.Separation stage 130 may comprise more than one individual separation.

The residual material from separation stage 130 consists of a mixture ofliquid products that includes produced water 138 (water with solubles)and an organic liquor 500. The organic liquor 500 is typically a liquidthat contains a mixture of carbon-containing species such as reactedliquid products from the first reaction. Preferably, most of theproduced water 138 is separated off, and a liquid product such as theorganic liquor 500 is directed to a third stage 140. Thus, the organicliquor preferably comprises a reacted liquid product, separated fromwater and in most instances also separated from reacted solid product.The produced water 138 contains numerous compounds including sulfur—andchlorine—containing materials and is preferably diverted forconcentration 139. It is desirable to separate out such compounds and,in preferred embodiments, concentration gives rise to a condensate 151(whose purity is usually better than that of municipal-strengthwastewater), and a concentrate 153 (that, in many instances, can be usedas liquid fertilizer similar to fish solubles).

Some of organic liquor 500 may be diverted to an optional separation 137to form specialty organic chemicals 143 such as fatty acids or aminoacids, for example via fractional distillation of the organic liquor.Residual fractions, fractionated liquor 145, often called ‘heavyliquor’, that comprises fractions that are not useful as specialtychemicals, may be redirected to third stage 140.

When the feedstock is municipal sewage sludge, the reacted feed 122 fromthe first stage reaction typically comprises produced water, a solidmatrix of organic and inorganic material, and a small amount of organicliquor. The produced water from municipal sewage sludge is then divertedfor concentration to form a product that finds application as afertilizer.

In a third stage 140, the organic liquor 500 is subjected to conditionswherein it undergoes a second reaction. It is also possible that theorganic liquor contains some quantity of reacted solid product that isalso passed to the third stage. Together, the organic liquor and reactedsolid product may be referred to as a solid matrix. In the secondreaction, the organic liquor is converted to a mixture of usefulmaterials that usually includes carbon solids 142, and a mixture ofhydrocarbons that is typically released as hydrocarbon vapor and gases148. Such a conversion may involve a decomposition of one or morematerials in the organic liquor. Suitable conditions in the third stagetypically use temperatures that are elevated with respect to the firststage, and use pressures that are reduced with respect to the firststage. The third stage typically does not involve the use of addedwater.

Carbon solids 142 are typically similar to coke, i.e., usually hardcarbonaceous materials with a high calorific value suitable for use as afuel. Carbon solids 142 preferably contain little, if any,non-combustible minerals that typically result from the incineration ofcarbon-containing materials in an oxygen-deficient atmosphere. Themineral content of carbon solids 142 is preferably less than 10% byweight, more preferably less than 5% by weight, still more preferablyless than 2% by weight, and most preferably less than 1% by weight.Where carbon solids 142 contain minerals, they may also be described asa carbon-mineral matrix.

The hydrocarbon vapor and gases 148 are referred to as “bio-derivedhydrocarbons” whenever biological material is the feedstock to theprocess of the present invention. The hydrocarbon vapor and gases can bevariously referred to as “tire-derived”, “rubber-derived” or“plastic-derived” if the raw feed stock comprises tires, rubber, orplastics, respectively. Hydrocarbon vapor and gases 148 typicallycomprise hydrocarbon gases, with possibly some trace impurities ofnon-hydrocarbon gases. The hydrocarbon gases include gases such asfuel-gas 146; the hydrocarbon vapors may be readily condensed to liquidsor oils 144 such as the lighter constituents of #2 diesel oil. One ofordinary skill in the art understands that a #2 diesel oil is an oilwith a relatively low viscosity or density.

When the feedstock is municipal sewage sludge, the solid products fromthe third stage typically comprise a mixture of hydrocarbon oils, fuelgas, and a mixture of minerals with carbon, in solid form.

It is to be understood that the operating parameters of the process ofthe present invention may be adjusted in one or more instances in orderto accommodate different types of raw feed materials. For example, inthe context of raw feed such as turkey offal, the major components areanimal fats, proteins, carbohydrates, and minerals. Thus, the balance ofthe major components may determine some aspects of the operatingconditions of the present invention. Furthermore, the temperature rangesof the first and third stage reactors can be controlled to producespecific products, thereby maximizing the economic value that can beobtained from the yield of various products.

An apparatus 200 for carrying out a process according to the presentinvention is shown in FIG. 2. Based on the teachings of the presentinvention, the assembly of the various components of apparatus 200 wouldbe within the capability of one of ordinary skill in the art of processengineering or chemical engineering. Accordingly, such technical detailsas would be familiar to an artisan of ordinary skill are omitted fromthe present description.

Feedstock preparation and slurrying may be carried out in a feedstockpreparation apparatus 210. After feed preparation and feed slurrying,the slurry is passed to a low pressure vented vessel 220 referred to asa feed storage tank. Preferably the feed is subjected to heating in orbefore the feed storage tank to produce a heated slurry that isoptionally subjected to pressurizing prior to entering the first stagereactor. Such heating and pressurizing typically take place in equipmentthat comprises a vessel to retain the slurry, a pump for increasing thepressure of the slurry, and a heat exchanger to heat the slurry.Typically conditions of about 140° F. and 1 PSI are employed, to keepthe feed slurry in a liquid state, and to limit biological activity. Ina preferred embodiment, the feed storage tank comprises a first tank anda second tank. In such a preferred embodiment, the first tank is heatedto a temperature of about 140° F. (about 60° C.) and subjected to apressure of about 1 p.s.i. Such conditions in the first tank effectivelybring about a cessation of biological activity. In an exemplaryembodiment, such a first tank may have a capacity of about 1,000,000U.S. gallons; thus, for a throughput of 100–150 gallons/minute, theeffective residence time in such a tank is about 700 minutes. The secondtank in such an embodiment may be maintained at a temperature of about300° F. and subjects the contents to a pressure of up to about 100p.s.i. The pressure is generally slightly above the saturation pressureof the mixture at a given temperature. For example, the saturationpressure of the mixture is 66 p.s.i. at about 300° F. (about 150° C.).The conditions in the second tank are typically harsh enough tobreakdown proteinaceous materials in the slurry, to loosen the slurry,and to drive off ammonia. The capacity of the second tank is typicallyless than that of the first tank, and may be as small as 2,500 U.S.gallons. Thus, in one embodiment, a flow rate of about 40 gallons perminute gives a residence time of about an hour in the second tank.Longer, preferred residence times for particular feedstocks, for exampleof several hours in the second tank, may be achieved with lower flowrates.

The first stage of the present invention is carried out in a first stagereactor 230, which preferably comprises a multi-chamber vessel so thatthere is a narrow distribution of residence times of the constituentmaterials of the slurry. In an alternate embodiment, the first stagereactor can also be an augured reactor. Preferably the vessel isequipped with baffles, and a multi-blade motorized stirrer that cansimultaneously stir the slurry in each of the chambers. In a preferredembodiment, there are four chambers in such a vessel. In anotherpreferred embodiment, the heating of the slurry takes place in severalstages ahead of this vessel.

The flashing of the reacted feed after the first reaction can beachieved in a flash vessel 240 (a “second stage separator”) with a vent.Preferably the pressure in the flash vessel 240 is considerably lowerthan that in the first stage reactor 230. In one embodiment, thepressure in the flash vessel is about 300 psi, where the pressure in thefirst stage reactor is around 600 psi.

Various equipment can be used to achieve various second stageseparations of the feed that comes out of the first stage reactor 230.Preferably such separations provide a mixture of steam and gases 132,organic liquor 500, minerals 134, and produced water with solubles 138.Steam and gases 132 are preferably diverted back to the preparationstage to assist with feed heating.

Separation of the minerals from the organic liquor and water can beachieved with centrifuges, hydrocyclones or with a static tank. Dryingof the minerals 134 can be achieved with, for example, a drying kiln orother mineral drier such as a “ring” dryer (not shown in FIG. 2). (In analternate embodiment, separation can be facilitated by adding a chemicalto break the emulsion.)

Produced water with solubles 138, resulting from the separation of theorganic liquor from the water, can be concentrated in an evaporator 250of a type that is typically available in the industry. The organicliquor 500 that has been separated from the minerals and the water maybe contained in an organic liquor holding vessel 252 prior to transferto the third stage reactor 260. Such a holding vessel may be an ordinarystorage vessel as is typically used in the industry.

Some portion of the organic liquor 500 may be diverted to give one ormore specialty chemicals. Typically this involves subjecting the organicliquor to fractional distillation. The organic liquor that is subjectedto fractional distillation is typically distilled in a distillationcolumn 254. The organic liquor may be subjected to an acid wash toseparate out trace amino acids before passing it to the distillationcolumn. More volatile materials from the organic liquor, such as fattyacids, are distilled off and collected. Any heavier materials such asnon-volatilized fats and fat derivatives that are found in the bottom ofthe distillation column are passed on to the third stage reactor 260.

The organic liquor that comes from the second stage separation is alsopassed to the third stage reactor 260 wherein a second reaction takesplace in which the organic liquor is converted into one or more usefulmaterials such as oil, and carbon solids 142. The oil that comes out ofthe third stage reactor may be subjected to further separation in aseparator 270, to produce oil 144 and fuel-gas 146. The separation maycomprise condensing the oil in various steps, and diverting it to oilstorage 280 in a storage vessel. The carbon solids 142 that come fromthe third stage reactor are cooled and may also be stored, or furtherheated and then treated to activate them according to methods that areknown to one of ordinary skill in the art. For example, the carbonsolids may be heated in an additional reactor, and be activated by theinjection of superheated steam.

As discussed hereinabove, exemplary raw feed materials include wasteproducts from the agricultural and food processing industries. Suchwaste products can comprise animal parts such as wings, bones, feathers,organs, skin, heads, blood and necks, soft tissue, claws and hair.Typical animal parts are those found in turkey offal and remnants ofcarcasses from slaughterhouses. Other waste products from the foodprocessing industry that are suitable for processing with the methods ofthe present invention include unused grease from fast foodestablishments such as burger franchises, and materials such asdissolved air flotation (“DAF”) sludge from food processing plants.Agricultural waste products can include animal dung or manure fromsheep, pigs, and cows, and also other materials such as chicken litterand crop residuals. In an exemplary embodiment illustrated in FIGS. 3–5,raw feed 100 is a food processing byproduct such as turkey offal.

As shown in FIG. 3, raw feed 100 is initially subjected to preparationand slurrying 110 to produce a feed slurry 112, accompanied by steam andgases 121. Slurry 112 may be transferred to feed storage 320 in a feedstorage tank (“FST” or homogenizer) via a heat exchanger 114. In theFST, the contents are preheated, typically to a temperature betweenabout 60° C. and about 150° C., in order to lower viscosity,biologically inactivate the slurry, and help mixing. The contents aremixed in the FST to produce conditioned feed slurry 322, a relativelyhomogeneous feed suitable for passing to the first stage reactor. Duringfeed storage, steam and gaseous impurities 338 are preferably vented336. Thus, one advantage of the present invention is that degassingoccurs in the FST so that unwanted gaseous impurities are removed at anearly stage in the overall process of the present invention. Feed slurry112 may remain in feed storage 320 for any convenient time until it isdue to be further processed by the methods of the present invention.Preferably, the FST supplies a constant feed stream to a high-pressureslurry pump that pressurizes the feed and transports it to the firststage reactor.

For raw feed materials that contain significant amounts of ammonia(NH₃), such as turkey offal, it is advantageous to remove the freeammonia, either during preparation 110, in which case it is onecomponent of steam and gases 121, or during storage 320, where it isvented along with steam and gaseous impurities 338. One source ofammonia is the breakdown of uric acid found in residual quantities ofurine that are often present in aggregates of animal body parts. Methodsof removing ammonia are within the knowledge of one of ordinary skill inthe art and include, but are not limited to, separation of the urinecontent prior to slurrying, use of enzymatic degradation, andapplication of heat. Additionally, ammonia can be converted byacidification to a salt such as ammonium sulfate, or ammonium phosphate.In a preferred embodiment, the FST comprises two vessels maintained atdifferent conditions. The first such vessel performs the role ofstorage; the second vessel effects the breakdown of proteins, andreleases ammonia.

The conditioned feed slurry 322 that emerges from feed storage 320 issubjected to a first reaction 330, wherein water content in theconditioned feed slurry 322 effects a hydrolysis of many of thebiopolymers present. Sufficient agitation (provided by mixers and/orrecirculation devices) is provided so that solids are kept insuspension. The first reaction typically takes from about 5 to about 60minutes. The output from the first reaction is a reacted feed 122.Typically steam and gas 339 are also released from the first reaction.

In the first reaction 330, some degasification takes place in whichpartial removal of nitrogen and sulfur compounds occurs, and deaminationand decarboxylation reactions can take place in which significantquantities of protein also dissociate into products such as ammonia, andpotentially carbon dioxide. In practice, for the process of the presentinvention, decarboxylation reactions are unwanted because the products,other than carbon dioxide, are amines which tend to be water soluble,and volatile. Thus, in general, deamination reactions are preferred todecarboxylation reactions, and the reacted liquid products obtained fromthe first stage typically include carboxylic acids when the feedstockincludes material such as proteins and fats. Accordingly, sincedecarboxylation reactions typically occur at higher temperatures thandeaminations, the first reaction is preferably run at the lowesttemperature possible at which fat molecules are split. As analternative, the pH in the first stage can be shifted by adding acid,thereby discouraging decarboxylation reactions.

Removal of the nitrogen and sulfur compounds at this stage, and theprior preheating stage, prevents formation of organic nitrogencompounds, ammonia, and various sulfur compounds that might becomeundesirable components of the resulting bioderived hydrocarbons ifallowed to become processed through the third stage reactor.

Typical conditions for carrying out the first reaction in this exampleare between 150° C. to 330° C., though preferably around 250° C., andaround 50 atmospheres pressure, or about 600 psi, as may be obtained ina first stage reactor. Generally, the pressure in the first stagereactor is in the range 20–120 atmospheres. The total preheat and firststage heating time is up to around 120 minutes. Such conditions may bevaried according to the feeds to be used. In one aspect of the presentinvention, as applied to feedstocks that contain PVC, the operatingtemperature in the first stage is high enough, and is followed bywashing steps, so that chlorine-containing products are removed.

Generally, the first reaction is carried out at temperatures in therange from about 150° C. to about 330° C. so that at least one of thefollowing three transformations can be carried out. First, proteins aretransformed to the individual amino acid residues of which they arecomposed. This can be achieved by hydrolyzing the peptide amide linkagebetween each pair of amino acid residues in the backbone of the proteinat temperatures in the range about 150–220° C. Second, fat molecules canbe broken down to fatty acid molecules, a process that can occur in therange of 200–290° C. Fats are hydrolyzed to split apart triglycerides toform free fatty acids and glycerol. Third, deamination anddecarboxylation of amino acids can occur in the first stage. Thecarboxylic acid groups, if allowed to proceed to the third stagereactor, still attached to their respective amino acid moieties, willall be converted to hydrocarbons at relatively mild operatingconditions. Additionally, there may be some amino acids that aredeaminated, a process that typically occurs in the temperature range210–320° C. Thus, in the first stage alone, virtually all the proteinpresent in the slurry will be converted to amino acids at relatively lowfirst stage operating temperatures. Furthermore, the degree of aminoacid deamination can be controlled by a judicious choice of first stageoperating temperature.

As would be understood by one of ordinary skill in the art, the actualconditions under which the first stage reactor is run will varyaccording to the feedstock employed. For example, animal offal typicallyutilizes a first reaction temperature in the range about 200° C. toabout 250° C. Municipal sewage sludge typically utilizes a firstreaction temperature in the range about 170° C. to about 250° C. Afeedstock comprising mixed plastics typically utilizes a first reactiontemperature in the range about 200° C. to about 250° C. Tires typicallyutilize a first reaction temperature in the range about 250° C. to about400° C. A typical operating condition for tire processing in the firststage reactor of the process of the present invention, would be at 275°C. and 300 psi, with a solvent to tire ratio of 1:1 or less by weight.Such a processing pressure for a given temperature is far lower thanthose reported in other methods of tire processing and is therefore moreeconomic.

The first stage of tire processing may also involve water for removal ofmaterials containing elements such as chlorine. Preferably suchmaterials are almost completely removed under normal operatingconditions. The tire material, solvent and water can be mixed togetherfor the first stage, or the tire may be contacted by the solvent and thewater sequentially.

The pressure in the first stage reactor is typically chosen to be closeto the saturation pressure of the water at the operating temperature inquestion. The saturation pressure is the pressure that needs to beapplied at a given temperature to keep the water from boiling, and alsodepends on the presence and quantity of other gases in the purified feedslurry. The total pressure in the reactor is greater than the vaporpressure of the water in the slurry mixture, so that the water does notboil off. The pressure is preferably in the range 45–55 atmospheres, maybe in the range 40–60 atmospheres, and may also be in the range 30–70atmospheres. Typically, the pressure is adjusted by amounts up to, andin the range of, 0–100 psi above saturation so that unwanted gases maybe vented 336 from feed preparation, feed storage, or the first stagereactor.

One advantage of the present invention is that the venting during thefeed preparation 110, feed storage 320, and first reaction permitsgaseous impurities such as ammonia, carbon dioxide, andsulfur-containing gases to be removed. Typically, the first reaction 330gives rise to sulfur-containing gases from the breakdown ofsulfur-containing moieties in the various bio-materials. A principalsource of sulfur is protein molecules, many of which have sulfur-bridgesbetween cysteine residues. The sulfur-containing gases are typicallyhydrogen sulfide (H₂S), and mercaptans (alkyl-sulfur compounds) such asmethyl mercaptan. Additionally, some salts such as calcium sulfide (CaS)may be produced, and these are normally separated during later stages.

After the first reaction, the reacted feed 122 that typically comprisesat least one reacted liquid product and at least one reacted solidproduct and water, is flashed 340 to a lower pressure, and permitted torelease excess heat back to the heating stages prior to the firstreaction. Typically, flashing is achieved through multiple pressurereductions, preferably in two to three stages. The effect of flashing isto vent off remaining steam and gases 132 associated with the reactedfeed. Dehydration via depressurization is efficient because water isdriven off without using heat. The effective use of the excess heat isknown as heat recovery, and represents a further advance of the processof the present invention. The fact that the first reaction uses water,which may be vented as steam, along with other gases 339, lends itselfto efficient energy recovery. Water and steam are effective in heatexchange and may be redirected to the heating stages before the firstreaction using one or more condensers. Condensers are quite compact andpromote efficiency. Thus, steam and gases 132 vented from the reactedfeed 122 are also preferably used to assist in heating the influent feedand in maintaining the temperature of the first reaction, therebyreducing the energy loss of the process of the present invention. Steamand gases 339 may also be passed to one or more heat exchangers placedprior to, or after, feed storage 320. Steam may also be directlyinjected back into the incoming feed 100 in some cases. Preferably,steam and gases 339 from first reaction 330 are combined with steam andgases 132 prior to passing to heat exchanger 114.

In the heat exchanger 114, the steam and gases are separated from oneanother. Most of the steam condenses to give a condensate 151.Preferably this condensate is redirected to combine with “producedwater” that results from later stages of the process of the presentinvention, further described hereinbelow. Residual, small, amounts ofsteam are vented 116 along with the gases. Preferably these vented gasesare combined with other gases that are produced by later stages of theprocess of the present invention to give fuel gas.

After the reacted feed has been flashed 340, and heat has beenrecovered, the intermediate feed 400 typically comprises at least onereacted liquid product, at least one reacted solid product, and water.The at least one reacted liquid product is typically a constituent of anorganic liquor; the at least one reacted solid product typicallycomprises minerals. The intermediate feed preferably is substantiallyfree of gaseous products.

FIG. 4 shows a sequence of separations that is applied to theintermediate feed. It is another advantage of the process of the presentinvention that the intermediate feed that results from the firstreaction is subjected to one or more separation stages that removesminerals and water before processing in the third stage reaction. Theseparation stage uses separating equipment such as centrifuges,hydrocyclones, distillation columns, filtration devices, and screens,and may also use distillation to remove very fine carbon solids from anintermediate feed 400. In general, further pressure reduction recoversmore steam, and facilitates solid/liquid separation to recover mineralsand other solids.

Intermediate feed 400, typically comprising organic liquor, water, andminerals is preferably subject to a first separation 410 that removesmost minerals 412 and produces a mixture of organic liquor and water 414that is low in ash. Such a separation is characterized as a solid/liquidseparation and may be achieved with a first centrifuge or via asolid/liquid separation device, for example by mechanical, ornon-mechanical methods such as gravity settling. Minerals 412 that areseparated out are typically wet and are thus subjected to a drying stage420 before passing to a dry mineral storage 430. The drying stagetypically takes place under normal atmospheric conditions. The resultingdry minerals may find considerable commercial application as a soilamendment or other industrial precursor.

The organic liquor/water mixture 414 is subject to a second separation440 to drive off the water and leave the organic liquor 500. Such asecond separation may be achieved using a second liquid/liquidcentrifuge (or other separation device). Differences in gravity allowcentrifugal separation of the produced water and organic liquor. Theproduced water 138 that is driven off contains significant amounts ofdissolved small organic molecules such as glycerol and some watersoluble amino acids that derive from the breakdown of proteins. Theproduced water also typically includes chloride impurities. Separatingout such impurities prior to the third stage reaction represents anadditional benefit of the present invention because later products arethereby not contaminated.

The produced water 138 may be subject to concentration 139, such as byevaporation, producing a water condensate 151 that may be recycledwithin the process of the present invention, and a concentrate 153 thatis dispatched to a concentrate storage 460. Evaporation is typicallyachieved by application of a slight vacuum. The concentrate, whichlargely comprises a slurry of amino acids, glycerol and, potentiallyammonium salts such as ammonium sulfate or phosphate, will typicallyhave commercial value as, for example, fertilizers known as “fishsolubles” that are sold in domestic garden stores.

It is to be understood that the present invention is not limited to aseparating stage comprising two steps. Nor is the present inventionlimited by the order in which any separation steps are carried out.Thus, it is consistent with the present invention if the separation ofthe intermediate feed 400 into products such as organic liquor,minerals, and water occurs in a single step or in more than two steps.Furthermore, minerals may, in some instances, be left in the organicfeed by design, and their separation thus need not occur prior to thirdstage processing.

When processing tires with an embodiment of the present invention, aportion of the organic liquor may be used as a final product that is adevulcanized tire feedstock for the manufacture of rubber products.

FIG. 5 shows a stage of the process of the present invention whereinorganic liquor 500 resulting from a separation stage of FIG. 4 issubject to a third stage 140 to produce one or more useful products. Theorganic liquor 500 ordinarily goes to a holding vessel before it isprocessed further.

A portion, or all, of organic liquor 500 can optionally be directed forprocessing ahead of the third stage 140 to yield one or more specialtychemicals 143. According to such an optional process, some desiredportion of organic liquor 500 is typically subjected to a separationprocess such as fractional distillation 510 or reacted with a compoundsuch as alcohol to form another compound, as would be understood by oneof ordinary skill in the art. Such a separation process generatesspecialty chemicals 143, and leaves behind a fractionated liquor 145,often referred to as a “heavy liquor”, that comprises higher molecularweight organic molecules such as triglyceride oils. Fractionated liquor145 may be redirected to the third stage 140 for processing in a similarmanner to organic liquor 500.

Specialty chemicals 143 are typically organic compounds such as fattyacids, fatty acid esters, fatty acid amides, or a range of amino acids.Preferably the specialty chemicals 143 are fatty acids. More preferably,specialty chemicals 143 are fatty acids in the range C₁₂₋₂₀. Even morepreferably, the specialty chemicals 143 are fatty acids in the rangeC¹⁶⁻²⁰. When the specialty chemicals 143 are fatty acid amides and fattyacid esters, they are typically formed by reaction with fatty acids. Thespecialty chemicals 143 resulting from a feedstock such as turkey offalmay find application as lubricants and coatings and paints.

In the third stage 140, the water content of the organic liquor 500 isalmost zero, so that the conditions of the third stage are such that theremaining organic molecules are broken down largely by application of ahigh temperature, rather than by hydrolysis by excess, or added, wateror steam. Typical conditions for carrying out the third stage are around400° C., as may be obtained in a third stage reactor. The third stagetypically takes from about 5 minutes to about 120 minutes. In practice,the various phases of the liquor spend varying amounts of time in thethird stage reactor. For example, the vapors pass through relativelyquickly, and the liquids take longer. The output from the third stagecomprises, separately, a mixture of hydrocarbon vapor and gases 148 suchas carbon dioxide, CO, and nitrogen and sulfur containing compounds, andcarbon solids 142. The carbon solids 142 preferably resemble highquality coke. The mixture of hydrocarbon vapor and gases 148 typicallycontains oil vapor. The conditions of the third stage are preferablyselected to optimize the purity of the carbon solids 142, and themixture of hydrocarbon vapor and gases 148. Rapid quench of hot vapors,such as the mixture of hydrocarbon vapor and gases 148, stops reactionsand minimizes carbon char formation after the third stage. In apreferred embodiment, rapid quenching of vapors may be achieved bydirecting the vapors into a drum full of water or by multiple quenchingsteps using thermal fluids and cooling mediums. Where such multiplequenching steps are employed, it is advantageous to take multiple cuts(diesel, gasoline, etc.) from the oil so that the various fractions canbe diverted to separate commercial applications. Alternatively, inanother embodiment, the oil vapor may be quenched in the presence of theincoming organic liquor, thereby also facilitating energy recovery.

Generally, the third stage is carried out at temperatures in the rangeof about 310° C. to about 510° C., so that at least one of the followingtwo transformations can be carried out. First, fatty acids are brokendown to hydrocarbons. This can be achieved by removing the carboxylgroup from each fatty acid molecule at temperatures in the rangeapproximately 316–400° C. Second, hydrocarbon molecules themselves are“cracked” to form a distribution of molecules of lower molecularweights, a process that can occur in the range approximately 450–510° C.Typically, however, hydrocarbon cracking occurs at temperatures above480° C. Preferably, the third stage is carried out at a highertemperature than that for the first stage. It would be understood thatthe temperatures described herein applicable to the third stage could bevaried without departing significantly from the principles of thepresent invention. For example, the third stage can be effectivelycarried out in the temperature range about 300–525° C., as well as inthe range 400–600° C. In some embodiments, the temperature of the thirdstage reactor is between about 400° C. and about 510° C.

Furthermore, in at least one embodiment, the third stage reactor isslightly pressurized, to a pressure between about 15 psig and about 70psig, i.e., from about 15 psi above atmospheric pressure, to about 70psi above atmospheric pressure. Preferably the pressure in the thirdstage reactor is lower than that in the first stage reactor.

Carbon solids 142 generated from the third stage are typically firstpassed to a carbon solids cooler 630 wherein the carbon is permitted tolose its residual heat. After cooling, the carbon solids 142 are passedto carbon storage 540 and may be sold for a number of usefulapplications. For example, the carbon may be sold as a “soil amendment”for use in domestic horticulture because many of the bacteria in soilneed a source of carbon. In particular, the carbon that is produced isof a quality similar to many forms of “activated carbon” and thus mayalso find application as a material for absorbing vapor emissions inautomobiles, or for use in domestic water filters. Additionally thecarbon, because of its level of purity, may find application as a solidfuel, like coal, but without the disadvantage of producing noxiousemissions arising from combustion of the contaminants typically found incoal products. Also many environmental toxicants can be neutralized in asoil matrix by the use of a carbon additive like the carbon solids thatresults from the process of the present invention.

Instead of, or in addition to carbon solids 142, a useful productgenerated by the process of the present invention can be clean coal.Clean coal is generated when the raw feed is raw coal. It has been foundthat coal fines produced by the process of the present invention areadvantageously freer of sulfur—and chlorine-containing contaminants thanraw coal typically available. These properties of the coal generated bythe process of the present invention makes them particularly attractiveas sources of clean-burning fuel.

The mixture of hydrocarbon vapor and gases 148 produced by the thirdstage reactor is typically directed to a cooler/condenser 850 whichseparates the mixture into fuel-gas 146 and a hydrocarbon oil 144. Thefuel-gas 146 has calorific value and may itself be redistributedinternally within the process of the present invention for the purposesof providing energy for heating at various stages or can be used toproduce electrical or other forms of energy for external or internaluse. The oil 144 typically comprises hydrocarbons whose carbon chainshave 20 or fewer carbon atoms. In this respect the mixture resembles thelighter components of a fuel-oil such as a #2 grade diesel oil. Such aproduct is also commercially saleable. It is to be understood, however,that the precise composition of the oil 144 depends upon the feedstock.Thus the composition of the oil obtained when the feedstock is composedof tires is different from the composition when the feedstock is turkeyoffal. It has been found that the oil resulting from feedstocks thathave a high fat content is rich in olefins, and di-olefins. If notdesired, such olefins may be removed from the oil by resaturation orseparation methods.

When the raw feedstock is tires, it has been found that the final stageoil obtained from hydrocarbon oil 144—in this case tire-derivedhydrocarbons—is a superior solvent for tires as compared to othersolvents presently utilized in the art. Following a general principle ofchemistry that “like dissolves like”, since the final stage oil comesultimately from the tires, its chemical nature is similar to theoriginal tires and so it is a good solvent for them. When the raw feedused with the process of the present invention comprises tires, at leastsome of the tire-derived hydrocarbons are redirected to the input rawfeed to assist with dissolving it prior to or during the preparation ofa slurry. Typically the tire-derived hydrocarbons have a boiling rangeof about 100° C. to about 350° C. In a preferred embodiment, thetire-derived hydrocarbons are heated prior to application to the tires.In another embodiment, the tire-derived hydrocarbons are applied to thetires and the mixture is heated to a temperature between about 200° C.and 350° C. The use of the final stage oil product eliminates therecurring costs of other solvents, and make-up quantities thereof.

In various embodiments of the present invention, the entire spectrum ofconstituents of the final stage oil or only a portion of theseconstituents can be used to dissolve tires. Preferably all of thetire-derived hydrocarbons are redirected to the input raw feed. Inanother embodiment, only the final stage heavy oil product is redirectedin this manner. If a portion of constituents is used, the separation ofthe solvent into parts can take place during either final stageprocessing or the 1st stage processing. The use of the final oil productas a solvent makes the process of the present invention far moreeconomic than other approaches. Because this oil will ordinarily not beavailable for the first batch of tires to be processed on any givenoccasion, another solvent may additionally be employed to assist withinitial breakdown of the tires. Such a solvent is toluene; others areknown to one of ordinary skill in the art.

When the raw feed is municipal sewage sludge, it is preferable tofacilitate the separation of the organic from the inorganic materials.Accordingly, in a preferred embodiment, some of the hydrocarbon oil 144,in this case bio-derived hydrocarbons, are redirected to the raw feed orthe product of the first reaction, in order to assist with floating thematerial. In other embodiments, materials such as trap grease, as areobtained from fast food outlets for example, can be used. The principlebehind floating the material is that a material that is lighter thanwater is introduced to the raw feed, or the product of the firstreaction, to assist with floating the heavier than water organicmaterials, thereby facilitating the separation of organic from inorganicmaterials. The result is a sludge that is easier to centrifuge thanwould otherwise be the case.

A further advantage of the process of the present invention is that allof the products are DNA and pathogen-free. That is, they are free ofpathological materials that are derived from animal cells, bacteria,viruses, or prions. Such materials do not survive the process of thepresent invention intact. This is an important outcome because there isno risk of using any of the products of the process of the presentinvention in agricultural applications where there would be a dangerthat such molecules could re-enter the food-chain.

An apparatus for converting reacted liquid product from the separationstage, such as an organic liquor, into a mixture of hydrocarbons, andcarbon solids, is a suitable third stage reactor for use with theprocess of the present invention. As shown in FIG. 6, a third stagereactor 600 according to an embodiment of the present inventioncomprises a heater 610 for heating the organic liquor, thereby producinga mixture of liquid and vaporized oil; a reactor 620 for converting themixture of liquid and vaporized oil into carbon solids 142, and amixture of hydrocarbon vapor and gases 148; a first cooler 630 foraccepting the carbon solids 142; and a second cooler 640 for acceptingthe hydrocarbon vapor and gases. Third stage reactor 600 mayadditionally comprise a fluid-solid separator 624 communicating withreactor 620 for separating hydrocarbon vapor and gases 148 from carbonsolids 142.

The heater 610 is preferably efficient and compact, comprising a largenumber of internal tubes that give rise to a large surface area for heatexchange. The heater 610 is typically a “fired heater”. Heater 610typically has an inlet for accepting organic liquor and steam 602, andan outlet for directing heated organic liquor/steam mixture to reactor620. Steam 602 in an amount approximately 2–5% by weight accompanies theorganic liquor as it enters heater 610. Such a quantity of steam helpsuniform heating and prevents residue build-up on the inside of theheater. In a preferred embodiment, one or more pre-heaters are used toheat organic liquor 500 prior to mixing it with steam and/ortransferring it to heater 610. Pressure for the third stage is impartedby a pump system after storage 500.

Reactor 620 preferably comprises at least one heated auger, and has andinlet and an outlet configured, respectively, to accept a heated mixtureof liquid and vaporized oil from heater 610, and to direct carbon solidsand a mixture of hydrocarbons and gases into a fluid-solid separator.The heated mixture of liquid and vaporized oil with steam is passed intothe reactor 620 where it splits into carbon solids, and a mixture ofhydrocarbon gases that preferably contains constituents of oil and fuelgas. Typically, the carbon solids produced amount to about 10% by weightof the mixture of liquid and vaporized oil. In other embodiments,depending upon the constituents of the raw feedstock, the carbon solidsproduced are between about 5% and about 20% by weight of the mixture ofliquid and vaporized oil. In some embodiments of the present invention,to avoid build up of excess carbon solids in reactor 620, the amount offeedstock processed is adjusted.

An auger is suitable for producing carbon solids and a mixture ofhydrocarbons because it permits control of residence time andtemperature of the incoming organic liquor, and because it permitsefficient separation of the carbon solids and the volatile products.Preferably the dimensions of the auger are selected so that the purityof the resulting hydrocarbon mixture and the carbon solids is optimized.For example, the cross-sectional diameter of the auger principallydetermines the rate of flow of vapors through it. Preferably the rate offlow is not so high that dust is carried through with the vapors toproduce an impure hydrocarbon mixture. The residence time of the heatedmixture of organic liquor, vapors and steam, as it reacts, alsodetermines the size of the auger.

Preferably the third stage reactor 600 includes a fluid-solid separatorthat communicates with the outlet of the reactor 620. The fluid-solidseparator preferably has a first outlet for hydrocarbons and gases, anda second outlet for carbon solids. Some of the fuel gas from the mixtureof hydrocarbons and gases is preferably redirected back to heater 610and burned to help maintain the temperature in the heater, therebypromoting overall efficiency of the process of the present invention.

The carbon solids—often at a temperature as high as about 500° C.—aredirected into a first cooler, carbon solids cooler 630, which ispreferably a cooling auger which communicates with the reactor throughan air lock device, or optionally the fluid-solid separator. In someembodiments of the present invention, more than one cooling auger 630may be employed. It is preferable to introduce water 632 into carbonsolids cooler 630 to assist with the cooling process. The carbon solidsare transferred to a finished product storage system 650, optionally viaa transfer auger or some other conveyancing device such as a bucketelevator 654 or to another heater/reactor to activate the carbon solids.

The second cooler 640 for accepting the mixture of hydrocarbon vapor andgases preferably comprises a carbon particulate separator for separatingout any residual carbon solids and returning them to reactor 620.

A modified version of the process of the present invention could be usedto inject steam into underground tar-sands deposits and then refine thedeposits into light oils at the surface, making this abundant,difficult-to-access resource far more available. Experiments alsoindicate that the process of the present invention can extract sulfur,mercury, naptha and olefins—all saleable commodities—from coal, therebymaking the coal burn hotter and cleaner. Pre-treating via the process ofthe present invention also makes some coals more friable, so less energyis needed to crush them prior to combustion in electricity-generatingplants.

For some feedstocks, the process of the present invention employs adevice for separating fine suspended solids from a fluid as part of thefeed preparation stage. In addition, many other industrial andcommercial applications require suspended solids to be separated from aliquid. FIG. 7 illustrates a separating device 700 according to apreferred embodiment of the invention that is useful for suchseparations. Another example of an application requiring the separationof a solid suspension is the separation of red and white blood cellsfrom whole blood. When the size of the suspended solid particles islarge, or their density is significantly different from that of thefluid, there are many different types of apparatus that can separatethem. For example, filters of many different configurations withopenings smaller than the suspended solid particles can be used forsolid material that does not deform significantly under strain.Clarifiers, settling chambers, and simple cyclones can be usedeffectively when there is a significant density difference between thesolid particles and the fluid. As the size or density difference becomesmaller, active devices using centrifugal forces can be effective.However, the efficiency of all these separating devices decreasesdramatically for very small particle sizes with deformable material thathas a density only slightly different from that of the suspending fluid.

With respect to a preferred process of the present invention, oneapplication where the suspended solids are small, deformable, and havesmall density difference is municipal sewage sludge (MSS). The suspendedmaterial in MSS consists primarily of cellular material and cellulardebris from bacteria and typically has dimensions of about 1 micrometer.This material is deformable and has an effective density within 10% ofthat of the suspending water medium. Separating this solid material fromwater is a preferred step in preparing MSS as a feedstock for theprocess of the present invention. Such separation may be achievedthrough use of centrifuges; however, in a preferred embodiment,separating device 700 is employed.

According to a preferred embodiment of the present invention, it ispreferable to employ separating device 700, as illustrated in FIG. 7,for separating solid and liquid components of a raw feed such as MSS,prior to further processing by the methods of the present invention.Such a device may also be applied to other industrial or commercialwastewater sludges whose solid particulates are deformable, or whoseeffective density is within about 10% of that of the liquid phase.

Device 700 preferably comprises a housing 702 that contains a spinningassembly 704 mounted in an inner chamber 706 having a frusto-conicalshape. The shape of inner chamber 706 typically comprises afrusto-conical section that has an angle of taper, with additionalsections at the base and/or at the top of the frustum that house otherparts of spinning assembly 704. The housing 702 preferably comprises aspinner case bottom 714 and a spinner case top 716 that are joined toone another, and that enclose the spinning assembly 704. Separatingdevice 700 further comprises an inlet 710 and a first outlet 730 thatcommunicate with the inner chamber, and a second outlet 750. Inlet 710permits introduction of the fluid that contains the suspended solidsinto an annular space 712 between a stationary inner wall 720 of theinner chamber, and the spinning assembly.

The spinning assembly comprises a frusto-conically shaped cylinder witha hollow interior, which is preferably made from a spinner bottom 722,connected to a tapered cylindrical wall 724 which itself is connected toa spinner top 718. The spinning assembly is concentrically mounted on alongitudinal axis 736 of a hollow spindle 726 which rotates at speedstypically in the range about 1,000 r.p.m. to about 50,000 r.p.m. In apreferred embodiment for separation of MSS, the rotation speed is about10,000 r.p.m. Preferably the rotation speed is chosen so as to minimizechaotic flow. The spinning assembly is tapered so that the effectivecross-sectional area decreases as the width narrows. Typically the angleof taper is between about 1° and about 10°. In a preferred embodiment,the angle of taper is between about 2° and about 2.5°, and is even morepreferably about 2.25°. The hollow interior of the spinning assemblycommunicates with a second outlet 750.

Preferably there is a pressure differential between the inlet 710 andthe interior of the separator device 700. Typically, this pressuredifferential is between about 3–150 p.s.i. and is controlled by twopumps (not shown in FIG. 7).

The flow rate for different sized separators will scale with the surfacearea of the rotating cylinder. Preferably, the inlet and the annular gapare configured to provide a flow rate between about 1 and about 200gallons per minute. More preferably, the flow rate is between about 1and about 20 gallons per minute. Even more preferably for handling MSS,the flow rate is about 10 gallons per minute.

The wall 724 of the spinning assembly is perforated. The pore size inthe wall 724 is typically between about 1 and about 200 micrometers.Preferably, the pore size is about 50 micrometers. The wall 724 ispreferably made of a plastic material such as HDPE or any other materialthat is not hygroscopic, to avoid closure of the pores during operation.

The fluid and suspended material flow along the annular passage 712 in agenerally axial direction while a portion of the fluid flows through theperforated rotating wall 724 into the hollow interior 728 of thecylinder. Hollow interior 728 communicates with hollow spindle 726through spindle inlet 732. Most of the suspended particles are preventedfrom flowing with the fluid through the perforated cylinder due to shearand centrifugal forces at the surface of the rotating cylinder. Therotational speed of the cylinder effectively sets the shear andcentrifugal forces on the suspended particles, and so can be used tocontrol the minimum size of the particle that can be prevented fromfollowing the fluid through the perforated cylinder. The water andparticles that flow into the interior of the cylinder 728 subsequentlyflow through spindle inlet 732 into the center of hollow spindle 726,and flow towards spindle outlet 734 before being discharged through asecond outlet 750.

The material in the annular passage 712 follows a tight spiral flow pathin response to the motion of the rotating cylinder. Preferably thethickness of annular passage 712 is constant along its length. For someapplications this annular space may vary from top to bottom. Variationsin annular space can impart flow conditions near the perforated spinnersurface. A first outlet 730 for discharging the now concentrated fluidstream is provided at the end of the annular passage away from theentrance.

The operation of the device of FIG. 7 is preferablyorientation-independent. In a preferred embodiment, the axis of thetapered cylinder is oriented vertically with the first outlet 730 at thebottom.

An advantage of the device of FIG. 7 over other separation devices knownin the art is that it can process sludges with a wide range of particlecharacteristics, in particular including those with deformable suspendedsolids in the size range below 1 micrometer or those that have densitieswithin 10% of the suspending fluid. In a preferred embodiment, theannular gap and the pore size in wall 724 are configured for separatinga suspension of municipal sewage sludge. In some embodiments of theprocess of the present invention, many such separators are used, inparallel, to achieve high throughput separation of a raw feedstock.

It is to be understood that the separator 700 depicted in FIG. 7 is notdrawn precisely to scale, though the various elements are in approximateproportion to one another. Thus, separator 700 may be constructedaccording to ordinary principles familiar to one of ordinary skill inthe art of mechanical engineering and design.

In a preferred embodiment, the outer diameter of spinner bottom 722 isabout 2″, and the outer diameter of the spinner top 718 is about 2.2″.The preferred length of spinner case bottom 714 is between about 7″ andabout 8″. The preferred length of spinner wall 724 is between about 4″and about 6″, and its preferred thickness is preferably constant alongits length and is about 1.5″. The preferred diameter of outlet 730 inconjunction with such a spinner is about 0.8″ and the outer diameter ofthe spinner case bottom is preferably about 3″. The outer diameter ofspinner case top is then preferably about 4″. Spindle 726 is hollow andpreferably has an inside diameter of about 0.25″. The outside diameterof spindle 726 may vary along its length and may be between about 0.5″and about 0.75″. The distance between spindle inlet 732 and spindleoutlet 734 may be about 6″ in such an embodiment. The thickness ofannular passage 712 is preferably about 0.05 to about 0.50 inches.

The preferred dimensions presented herein are to be taken as but oneillustration, and, according to design choice and desired throughput, amechanical engineer of ordinary skill in the art would be able to scaleup or down the size of the various elements of separator 700 in order toachieve operating efficiency.

The overall apparatus for carrying out the process of the presentinvention is preferably accompanied by a computerized control systemthat comprises simple controllers for valves, pumps, and temperatures.Development of such a system is within the capability of one of ordinaryskill in the art of computer process control engineering.

The apparatus of the present invention may be scaled according to need.For example, plants that handle many thousands of tons of waste per daycan be envisioned, whereas portable plants that could be transported onthe back of a flatbed truck and that might only handle one ton of wasteper day can also be built.

EXAMPLES Example 1

Pilot Plant

A pilot plant has been built employing apparatus and processes of thepresent invention. The pilot plant can handle approximately seven tonsof waste per day.

According to one exemplary application of the pilot plant, theexperimental feedstock was turkey processing-plant waste: feathers,bones, skin, blood, fat, viscera. An amount of 10,044 pounds of thismaterial was put into the apparatus's first stage: a 350-horsepowergrinder, which turns the material into gray-brown slurry. From there,the material flowed into a series of tanks and pipes which heated andreformed the mixture.

Two hours later, a light-brown stream of steaming fine oil was produced.The oil produced by this process is very light. The longest carbonchains are C₂₀. The produced oil is similar to a mix of half fuel oil,half gasoline.

The process of the present invention has proved to be 85% energyefficient for complex feedstocks such as turkey offal. This means thatfor every 100 B.t.u. (British thermal units) in the feedstock enteringthe plant, only 15 B.t.u. are used to run the process. The efficiency iseven better for relatively dry materials, such as carbon-heavy ormoisture-light raw materials such as plastics.

The first stage reactor, comprises a tank approximately 20 feet tall,three feet wide, and heavily insulated and wrapped with electric-heatingcoils. In the first stage reactor, feedstock is hydrolyzed by means ofheat and pressure. Both temperatures and pressures are not very extremeor energy-intensive to produce because water assists in conveying heatinto the feedstock. It usually takes only about 15 minutes for thisprocess to occur in the pilot plant.

After the organic materials are heated and partially depolymerized inthe reactor vessel, a second stage begins. In this phase, the slurry isdropped to a lower pressure. The rapid depressurization instantlyreleases about half of the slurry's free water. Dehydration viadepressurization is far more efficient than heating and boiling off thewater, particularly because no heat is wasted. Water that is“flashed-off” is sent up a pipe that leads back to the beginning of theprocess to heat the incoming process stream.

In this second stage, the minerals settle out, and get shunted tostorage tanks. In turkey waste, these minerals come mostly from bones.The minerals come out as a dried brown-colored powder that is rich incalcium and phosphorous. It can be used as a fertilizer because it iswell-balanced in micro-nutrients. In particular it has a useful range ofmicro- and macro-nutrients. The minerals contain the correct amounts ofelements such as calcium and phosphorous required for healthy plantgrowth and development.

In the pilot plant, the remaining concentrated organic materials flowinto a third stage reactor and is subjected to third stage processing,as described hereinabove. Gases resulting from the processing were usedon-site in the plant to heat the process of the present invention. Theoil and carbon flow into storage as useful higher value products.

Depending on the feedstock and the first and third stage processingtimes, the process of the present invention can make other specialtychemicals, which are extracted at various sections of the process.Turkey offal, for example, can make fatty acids for use in soap, tires,paints and lubricants.

Example 2

Operating Plant

A full-sized commercial-scale installation is under construction,intended to process over 200 tons of turkey-waste daily. The plant isdesigned to produce about 10 tons of gas per day, which returns to thesystem to generate heat to power the system. The plant will produceabout 21,000 gallons of water, which is clean enough to discharge into amunicipal sewage system, and is also free of pathological vectors. Theplant also will make about 25 tons of minerals, concentrate and carbon,and about 500 barrels of high-quality oil of the same grade as a #2heating oil.

Example 3

Exemplary Conversions of Waste Products

Table 1 shows end-products, and their proportions, for 100 lbs of eachof the following waste product, when they are converted to usefulmaterials using the process of the present invention: Municipal SewageWaste (comprising 75% sewage sludge and 25% grease-trap waste); Tires;Poultry Processing Waste (comprising organs, bones, blood, feathers andfat); Plastic bottles (comprising a blend of Polyethylene Terephthalate(PET) used to make soda bottles, and High Density Polyethylene (HDPE)used to make milk jugs); Paper; Medical Waste (originates primarily fromhospitals and comprises plastic syringes, transfusion bags, gauze, paperwrappers and wet wastes); and Heavy Oil (such as refinery-vacuumresidues and tar sands). Amounts in Table 1 are in pounds.

TABLE 1 Feedstock Oil Gas Solids & Concentrate Water Municipal Sewage 26 9  8 (carbon and mineral 57 Sludge   solids)† Tires 44 10 42 (carbonand metal solids)  4 Poultry Processing 39  6  5 (carbon and mineralsolids) 50 Waste Plastic bottles 70 16  6 (carbon solids)  8 Paper‡  848 24 (carbon solids) 20 Medical Waste 65 10  5 (carbon and metalsolids) 20 Heavy Oil 74 17  9 (carbon solids). — ‡For paper, the figuresare based on pure cellulose; it is estimated that yields for specificpaper feedstocks such as newspapers or office waste paper would bewithin 10% of these figures. †The solid output from municipal sewagesludge may also contain heavy metals.

It is worth noting that the yields from cattle and pork processingwastes are similar to those from poultry processing waste.

Example 4

Removal of Contaminants from Coal Fines and High Sulfur Coal.

Low detection mercury analysis was carried out on raw fines, high sulfurcoal, and on the products of the process of the present inventionapplied to each. In each case the detection limit was 0.01 ppm. Fromcoal fines raw feed, the mercury level was 0.12 ppm; mercury was notdetectable in the processed carbon.

From high sulfur coal raw feed, the mercury level was 0.02 ppm; mercurywas not detectable in the processed carbon.

Example 5

Removal of Sulfur Contaminants from Coal Fines

Unprocessed fines contained 1.71% sulfur. Composite carbon contained1.58% sulfur, a 7.6% reduction from the unprocessed fines. Carbonproduced by one application of the process of the present inventioncontained 1.51% sulfur, a 11.6% reduction from the raw feed.

Example 6

Removal of Sulfur Contaminants from High Sulfur Coal

Raw feed high sulfur coal contained 2.34% sulfur by weight. After oneapplication of the process of the present invention, the resulting solidproduct contained 2.11% sulfur by weight.

Example 7 Removal of Contaminants from Low Sulfur Coal

Unprocessed coal contained 1.08% sulfur; carbon obtained from theprocess of the present invention contained 0.49% sulfur, a reduction of54.6%. A very low concentration of sulfur (45 ppm) was also detected inproduced water.

In another application of the process of the present invention to thesame sample, carbon contained 0.57% sulfur, a reduction of 47.2%. Theproduced gas (the gas discharged from the process) from this applicationcontained 0.9% sulfur by weight, thus illustrating that the sulfurdriven off ends up largely in gaseous products.

It is significant that as much as about half of the sulfur-containingcontaminants can be removed when the initial sulfur-content is alreadyvery low.

The process of the present invention is also effective at removingmercury. Mercury was essentially absent from carbon produced by theprocess of the present invention, where detection levels to about 10 ppbwere possible. Mercury was detected in the produced water at levels of30 ppb (0.028 ppm) demonstrating that when mercury is removed from coal,it is transferred to water. When the mercury is in the water, it isamenable to safe disposal. The water is stripped of hydrocarbons, andconcentrated down by use of a vacuum distillation unit. The resultingmercury-concentrated water is subject to silicate crystallization andthe resulting highly insoluble silicate crystals would be containerizedand stored in a hazardous waste site rated for storage of toxic metals.

Example 8

A Bio-derived Oil

A bio-derived oil can be produced from a wide range of organic materialsusing the process of the present invention. One such bio-derived oilcomes from turkey offal, comprises C-20 and shorter carbon-chaincomponents, and virtually eliminates particulate emissions when used asa fuel. This oil provides refineries or blenders with a narrow range40-plus American Petroleum Institute (API) renewable oil that can beused as an alternative fuel, or a blending component for combustiblefuels. Salient properties of this oil are shown in Table 2, wherein thespecification methods are designated by an ASTM (American Society forTesting Materials) code.

TABLE 2 Specification Fuel Property Method Bio-derived Oil API Gravityat 60° F. D-287      40+ Flash Point (° F.) D-93     100 Distillation,Recovery, ° F. (Typical) D-86 Initial Boiling Point, ° F.     125 10%    160 20%     220 30%     280 40%     335 50%     400 60%     450 70%    500 80%     580 90%     660 Recover, Vol. %      95% AppearanceD-4176 Clear and Bright Cloud Point ° C. D-2500    −10 Pour Point ° C.D-97    −20 Viscosity @ 40° C., cSt D-445    ~1.50 Sulfur, Wt. % D-4294   <0.15 Copper Corrosion Rating D-130    <2 (2 hrs @ 212° F.) CetaneIndex D-976    ~40 BS&W (Basic Sediment and water), D-2709    <0.10 Vol.% Ash, Wt. % D-482    <0.005 Carbon Residue, Wt. % D-524    <0.50 HeatContent, BTU/1b D-240 ~18,800 PONA, Wt. % (Typical) D-5443 Paraffins     22 Olefins      14 Naphthenes      3 Aromatics      6 C-14/C-14+     55

In Table 2, the weight percent of paraffins, olefins, naphthenes, andaromatics refer to molecules that contain up to and including 13 carbonatoms.

Example 9

Embodiment of a Third Stage Reactor and Cooler/Con Denser

FIGS. 8A and 8B show an embodiment of an apparatus for use with theprocess of the present invention. Some elements are also shown in FIG.6.

FIG. 8A shows an apparatus for use with the third stage of the processof the present invention. Organic liquor 500 passes into a storage tank812. Optionally, organic liquor and oil may be directed to aliquid/liquid separator 814 and divided into a first portion offractionated liquor/oil 816 and a second portion of, or residual,fractionated liquor/oil 822. The first portion of fractionatedliquor/oil may be directed to finished product storage 818, anddistributed as fractionated liquor/oil 820 which can be recycled orsold. The second portion of fractionated liquor/oil 822 is redirected toone or more preheaters 830.

Having been heated, the fractionated liquor/oil 822, or the unseparatedliquor/oil 500 is passed to a heater 610, preferably accompanied bysteam 602. Resulting liquid and vaporized liquor/oil 836 is passed to areactor 620, such as an auger, and separated into hydrocarbon vapor andgases 148, and carbon solids 142. The hydrocarbon vapor and gases 148are passed to a cooler/condenser 850, which is further described in FIG.8B. Any remaining particulates in the oil vapor and gases, such asresidual carbon solids 844, are removed and returned to the reactor 620.

Carbon solids 142 are directed through an air lock 846, and into acarbon solids cooler 630, wherein they are mixed with water 632. Theresulting mixture of water and carbon solids is passed through anotherair lock 854 into a finished product storage system 650. Final productcarbon solids 142 may be distributed to one or more commercialapplications.

For use in conjunction with apparatus 800 shown in FIG. 8A, is acooler/condenser 850, shown in FIG. 8B. Cooler/condenser 850 facilitatesa number of separation cycles wherein a mixture of oil vapor and gases,which may also contain water and particulates, is subject to a number ofdifferent separation steps. Hydrocarbon vapor and gases 148 from reactor620 pass into a carbon particulate separator 842, which separates outremaining solid particles, such as residual carbon solids 844, andredirects such solids back to reactor 620.

The hydrocarbon vapor and gases that emerge from the carbon particulateseparator pass into a vapor quenching system 860, implemented accordingto general principles that would be understood by one of ordinary skillin the art. From the vapor quenching system, oil and gases 870 pass intoan oil/water/gas separator 872 which further separates the variouscomponents such as oil 862, slop oil 876, gas and LPG 874, and anoil/carbon slurry 881.

Oil 862 passes to a heat exchanger 864 and thereafter into a finishedproduct storage system 866, and is sold as oil 144.

Gas and liquid petroleum gas (“LPG”) 874 pass into a condenser 890 whichseparates out LPG 898 from the other gaseous components. Gas 894 ispassed to super heater 892 to yield a fuel gas 146, which can bedelivered to one or more devices as a source of energy. LPG 898 isrecycled in the following way. First, LPG 898 is passed through aliquid/solid separator 884, and any residual carbon solids 886 areremoved. Then, the separated LPG, mixed with oil separated from theoil/carbon slurry 881, is returned to the oil/water/gas separator 872,and a further separation takes place. The cycle wherein the gas and LPGmixture is separated and condensed may be repeated as many times as isdesired.

An oil/solid mixture, typically an oil/carbon slurry 881, may also bedirected from oil/water/gas separator 872 to liquid/solid separator 884in order to remove residual carbon solids 886. The separated oil, mixedwith LPG, is preferably returned to the oil/water/gas separator forfurther redirection, as appropriate.

Slop oil 876 from oil/water/gas separator 872 is passed to an oil/waterseparator 878, and water 880 is released, or may be recycled. Oil 882from the oil/water separator is passed back to the oil/water/gasseparator for further iterations of the separation cycle.

The foregoing description is intended to illustrate various aspects ofthe present invention. It is not intended that the examples presentedherein limit the scope of the present invention. The invention now beingfully described, it will be apparent to one of ordinary skill in the artthat many changes and modifications can be made thereto withoutdeparting from the spirit or scope of the appended claims.

1. An apparatus for separating particulates from a fluid in asuspension, comprising: a housing defining a frusto-conically shapedinner chamber with an inner wall, an inlet and a first outletcommunicating with said chamber, and a second outlet; and a spinningassembly with a hollow interior mounted in the chamber, said assemblybeing shaped to define an annular gap with the chamber inner wall, saidhollow interior communicating with the second outlet, and said hollowinterior communicating with said annular gap for flow of fluid materialsfrom said gap into said interior and out of said second outlet inresponse to rotation of the spinning assembly, wherein said spinningassembly comprises a hollow spindle forming a tube-like structureextending inside of said spinning assembly and defining a spindle inletlocated within the spinning assembly and a spindle outlet, said spindleoutlet communicating with said housing second outlet, and a tapered,porous cylindrical wall mounted on said hollow spindle to define saidhollow interior, the hollow interior communicating with said hollowspindle through said spindle inlet, wherein the hollow spindle forms atube-like structure that extends along the entire length of the porouscylindrical wall and the spindle inlet is thereby disposed within saidporous cylindrical wall and wherein the spindle inlet is disposed at alevel below the inlet and above the first outlet.
 2. The apparatus ofclaim 1 wherein said spinning assembly rotates at a speed of about10,000 r.p.m.
 3. The apparatus of claim 1 wherein said spinning assemblyrotates at a speed between about 1,000 r.p.m. and about 50,000 r.p.m. 4.The apparatus of claim 1 wherein the annular gap is substantiallyconstant along its length.
 5. The apparatus of claim 1 wherein theannular gap is of variable thickness.
 6. The apparatus of claim 1wherein the tapered porous cylindrical wall has a pore size of betweenabout 1 and about 200 microns.
 7. The apparatus of claim 6 wherein thepore size is about 1–100 microns.
 8. The apparatus of claim 6 whereinthe pore size is about 50 microns.
 9. The apparatus of claim 1 whereinsaid annular gap and said porous wall pores are sized for separating asuspension of municipal sewage sludge.
 10. The apparatus of claim 1wherein said cylindrical inner wall is tapered at an angle of from about1° to about 10°.
 11. The apparatus of claim 10 wherein the angle isbetween about 2° and about 2.5°.
 12. The apparatus of claim 1 whereinthere is a pressure differential between the inlet and the annular gap.13. The apparatus of claim 12 wherein the pressure differential is about3–4 p.s.i.
 14. The apparatus of claim 1 wherein the inlet and annulargap are configured and dimensioned for a flow rate between about 1 andabout 20 gallons per minute.
 15. The apparatus of claim 14 wherein theflow rate is about 10 gallons per minute.
 16. An apparatus forseparating particulates from a fluid in a suspension, comprising: acasing having an inner surface; a tapered cylinder disposed in thecasing, having a longitudinal axis, an angle of taper, and having aporous wall with an outer surface configured to form an annular gapbetween the outer surface and the inner surface of said casing, saidtapered cylinder being concentrically mounted on a hollow spindle thatextends along the entire length of said cylinder wall so that saidtapered cylinder can be caused to rotate about its longitudinal axis; aninlet for introducing the suspension into the annular gap at a flowrate; a first outlet in the casing for permitting separated particulatesto be released from the device, upon rotation of the cylinder; a secondoutlet in the hollow spindle for permitting fluid that passes throughthe porous wall to be drained from the device, upon rotation of thecylinder; and a pump communicating with the inlet to provide a pressuredifferential between the inlet and interior of the casing, wherein saidhollow spindle has a spindle inlet that is disposed at a level below theinlet and above the first outlet.
 17. The apparatus of claim 16, furtherwherein said pressure differential is between about 3–150 psi.
 18. Theapparatus of claim 16, wherein said hollow spindle forms a tube-likestructure extending inside said tapered cylinder and defines a hollowspindle inlet inside said tapered cylinder.